Diagnostic performance of loop-mediated isothermal amplification (LAMP) and Ultra-sensitive PCR in diagnosis of malaria in western Saudi Arabia

Malaria diagnosis continues to be one of the most important steps in the cycle of control specially in endemic countries with low parasitic load infections. Loop-mediated isothermal amplification (LAMP) and ultrasensitive PCR (Us-PCR) are two promising candidates for malaria diagnosis. A cross sectional study performed at King Faisal Hospital, Taif KSA involved patients suffering from signs and symptoms suggesting of malaria, 35 blood samples diagnosed by Nested Multiplex PCR as a reference method (13 P. falciparum, 17 P. vivax, 3 mixed P. falciparum and P. vivax) plus two negative controls were selected to be included in this study to analyse the performance of two LAMP methods (LAMP OptiGene (R) and LAMP WarmStart (R)) and two ultrasensitive PCRs (Us-PCR TARE-2 and Us-PCR Var-ATS). LAMP OptiGene (R) and LAMP WarmStart (R) performances were identical and better than the performance of Us PCR TARE 2 and Us-PCR var-ATS for P. falciparum, achieving 93.75% sensitivity, 100% specificity and 97.17% accuracy versus 87.5% sensitivity, 100% specificity and 94.29% accuracy for the Us PCR TARE 2 and 81.25% sensitivity, 94.74% specificity and 88.57% accuracy for the Us PCR var-ATS respectively. In P. vivax diagnosis LAMP OptiGene (R) performed excellently with 100% sensitivity, specificity, and accuracy while LAMP WarmStart (R) and Us-PCR Cox1 achieved 100% sensitivity, specificity 93.33% and 97.14% accuracy. The study results highlighted the benefits of using LAMP techniques for field diagnosis of malaria in different settings where the need for a more sensitive and reliable molecular tool is mandatory but at the same time removing the high cost, long turnaround time and the need of highly specialized trained technicians to perform more sophisticated molecular techniques.